Sir,A 65-year-old man presented with recurrent generalized itching since 1 year. Examination revealed lichenified skin over the face and extensors of both extremities. He gave a history of rubbing the pulp of Aloe vera leaves on to his lesions whenever his itching worsened. Clinically, we suspected allergic contact dermatitis, possibly aggravated with Aloe vera. He was patch tested with the plant series by CODFI, which included parthenium 0.5%, xanthium 0.5%, chrysanthemum 0.5%, control and pulp of Aloe vera, and the results were interpreted as recommended by ICDRG. He tested positive to Aloe vera on day 2 and day 3. One of the authors (CRS) tested negative to the pulp, thus ruling out irritant dermatitis.

Allergic contact dermatitis to Aloe vera has been reported earlier.[1],[2] The gelatinous material inside the leaf of Aloe vera has been recommended from ancient times for the alleviation of inflammatory changes in the skin.[3] More recently it has been advocated in the treatment of radiodermatitis and leg ulcers.[4] It is a common ingredient in numerous topical moisturizers (e.g. Elovera, Sofderm, Dewderm). Aloe consists of a variable mixture of aloin, aloemodin and other substances.[3] Aloin is an anthraquinone that may be regarded as a potential sensitizer.[3]

This report highlights the fact that even commonly used, relatively safe medications can occasionally cause sensitivity.